Meghan Trainor, the 20-year-old who is having a pop culture moment with the song about body acceptance, said she initially wrote the track and pitched it to other artists, but was turned away.

"Labels were like, 'We love it, but you have to reproduce it. You got to get it more synth-y, pop-y,'" said Trainor, who worked with producer Kevin Kadish on "Bass." ''We looked at each other like, 'Man, I thought this was a hit, but I guess not.'"

Things changed when record executive L.A. Reid heard the doo-wop pop song and told Trainor she should be the voice behind it. He signed the budding songwriter to Epic Records after hearing her sing "Bass" while playing the ukulele.

This week, the song jumped 20 spots on the Billboard Hot 100 chart to No. 8. The single has sold 389,719 copies so far in five weeks, and the music video, which has 10 million views and climbing, has become a water cooler topic among young girls and parents.

"Bass" features standout lines like "it's pretty clear, I ain't no size two," ''I'm bringing booty back" and "yeah my momma, she told me don't worry about your size." Trainor said Grammy-nominated Kadish, who has worked with Jason Mraz, had the song title but didn't know where to go from there.

"And I immediately thought, 'Booty. Bass. Thickness,'" she said.

Trainor, who grew up in Nantucket, Massachusetts, recently moved to Nashville, Tennessee. She was signed to a publishing house in Music City, and wrote songs for Rascal Flatts and others. Now, she's working on an EP and album to capitalize on the breakthrough that "Bass" has given her.

Trainor said she's ecstatic and humbled that young girls have gravitated to the song.

"I tear up and I call my mom like, 'Did you see that? Did you read that one?' because some girls are like, 'I've hated myself. I hated life. I didn't want to go to school. I get bullied. And then I heard your song and I cried,'" she said. "They say they cried because they're happy and they dance around the room. And I was just like, 'What?' It's crazy."

"Bass" has given Trainor a boost as well.

"I wish there was a song like this when I was 13," she said, adding that she's not always confident. "It's all mostly in my head. I would sit there in class like, 'I know they are judging me right now. I know they're picking on me.' … So it helped me a lot, watching this video and seeing the comments that were positive. It's helped me go up a little bit."